Installations of natural gas transformation, or the fractionators, are employed to purify natural gas vintage extracted starting from the underground gas layers and brought to surface by gas wells. The treated natural gas, used as fuel by the residential, commercial consumers and industrial, is almost pure methane and is much different from believed natural gas. The believed natural gas consists typically mainly of methane (CH4), the lightest hydrocarbon molecule shortest and. It also contains variable quantities of: Heavier gas hydrocarbons: ethane (C2H6), propane (C3H8), normal butane (n-C4H10), isobutene (i-C4H10), pentanes and still higher hydrocarbons of molecular weight. Once transformed and purified into finished by-products, all the latter is NGL collectively noted (natural gas liquids). Acid gases: carbon dioxide (CO2), hydrogen sulphide (H2S) and mercaptans such as methanethiol (CH3SH) and ethanethiol (C2H5SH). Other gases: nitrogenize (N2) and helium (it). Water: and water steam of liquid.
Liquid hydrocarbons: perhaps oil condensate (also indicated under the name of the gasoline of head of envelope or the normal gasoline) and/or rough of a certain natural gas.
Mercury: a little mercury very mainly in elementary form, but the chlorides and other species are probably present.
The believed natural gas must be purified to answer the standards of quality indicated by the principal companies of transmission and distribution of drain. These standards of quality change drain with the drain and are related usually to market and systems designs of drain which it serves. In general, the standards indicate that the natural gas: Be in a specific margin of calorific value (heating value). For example, in the United States, it should be approximately 1.035 ± 5% Btu per cubic foot of gas to the 1 atmosphere and °F 60 (41 MJ ± 5% per cubic meter of gas to the 1 atmosphere and 0 °C). Be delivered or above behind a temperature indicated of point of hydrocarbon condensation Be of particulate solids and liquid water to prevent erosion, corrosion or other damage with the drain.
Be dehydrated steam sufficiently to prevent the formation of the methane hydrates within the installation of transformation of gas or later in the drain of gas transmission of sales. Do not contain more than traces of components such as the hydrogen sulphide, the carbon dioxide, the mercaptans, the nitrogen, and the steam. Maintain mercury in extreme cases less than discernible (roughly 0.001 ppb by volume) mainly to avoid the equipment prejudicial in the installation of gas transformation or the system of transmission of drain of the mercury amalgamation and embitterment of aluminum and other metals.